ios枚举的定义与使用

定义

在类的.h文件中，

一. NS_ENUM，定义状态等普通枚举

typedef NS_ENUM(NSUInteger, myKeyBoardType) {
    KeyBoardTypeDefault = 0,
    KeyBoardTypeNumber,
    KeyBoardTypeEmail
};

····

／*与枚举命名相同的属性
@property(nonatomic,assign)NSUInteger myKeyBoardType;

······

/ *重写属性myKeyBoardType的set方法
-(void)setKeyboardType:(NSUInteger)keyboardType{
    
    switch (keyboardType) {
        case 0:
            _inputTF.keyboardType = UIKeyboardTypeDefault;
            break;
        case 1:
            _inputTF.keyboardType = UIKeyboardTypePhonePad;
            break;
        case 2:
            _inputTF.keyboardType = UIKeyboardTypeEmailAddress;
            break;
            
        default:
            break;
    }
    
}

二. NS_OPTIONS，定义选项

/*typedef NS_OPTIONS(NSUInteger, TTGDirection) {
    TTGDirectionNone = 0,
    TTGDirectionTop = 1 << 0,
    TTGDirectionLeft = 1 << 1,
    TTGDirectionRight = 1 << 2,
    TTGDirectionBottom = 1 << 3
};*/

使用

在需要的地方导入类文件，

外界对属性myKeyBoardType进行赋值时，会直接提示枚举中的选项。

应用——根据不同类型创建按钮

创建一个uibutton分量
.h中

typedef NS_ENUM(NSUInteger, MKButtonEdgeInsetsStyle) {
    MKButtonEdgeInsetsStyleTop, // image在上，label在下
    MKButtonEdgeInsetsStyleLeft, // image在左，label在右
    MKButtonEdgeInsetsStyleBottom, // image在下，label在上
    MKButtonEdgeInsetsStyleRight // image在右，label在左
};

@interface UIButton (ImageTitleSpacing)

// 添加创建方法
- (void)layoutButtonWithEdgeInsetsStyle:(MKButtonEdgeInsetsStyle)style
                        imageTitleSpace:(CGFloat)space;

@end

.m中，实现创建方法

- (void)layoutButtonWithEdgeInsetsStyle:(MKButtonEdgeInsetsStyle)style
                        imageTitleSpace:(CGFloat)space
{    
    /**
     *  前置知识点：titleEdgeInsets是title相对于其上下左右的inset，跟tableView的contentInset类似，
     *  如果只有title，那它上下左右都是相对于button的，image也是一样；
     *  如果同时有image和label，那这时候image的上左下是相对于button，右边是相对于label的；title的上右下是相对于button，左边是相对于image的。
     */
    
    // 1. 得到imageView和titleLabel的宽、高
    CGFloat imageWith = self.imageView.frame.size.width;
    CGFloat imageHeight = self.imageView.frame.size.height;
    
    CGFloat labelWidth = 0.0;
    CGFloat labelHeight = 0.0;
    if ([UIDevice currentDevice].systemVersion.floatValue >= 8.0) {
        // 由于iOS8中titleLabel的size为0，用下面的这种设置
        labelWidth = self.titleLabel.intrinsicContentSize.width;
        labelHeight = self.titleLabel.intrinsicContentSize.height;
    } else {
        labelWidth = self.titleLabel.frame.size.width;
        labelHeight = self.titleLabel.frame.size.height;
    }
    
    // 2. 声明全局的imageEdgeInsets和labelEdgeInsets
    UIEdgeInsets imageEdgeInsets = UIEdgeInsetsZero;
    UIEdgeInsets labelEdgeInsets = UIEdgeInsetsZero;
    
    // 3. 根据style和space得到imageEdgeInsets和labelEdgeInsets的值
    switch (style) {
        case MKButtonEdgeInsetsStyleTop:
        {
            imageEdgeInsets = UIEdgeInsetsMake(-labelHeight-space/2.0, 0, 0, -labelWidth);
            labelEdgeInsets = UIEdgeInsetsMake(0, -imageWith, -imageHeight-space/2.0, 0);
        }
            break;
        case MKButtonEdgeInsetsStyleLeft:
        {
            imageEdgeInsets = UIEdgeInsetsMake(0, -space/2.0, 0, space/2.0);
            labelEdgeInsets = UIEdgeInsetsMake(0, space/2.0, 0, -space/2.0);
        }
            break;
        case MKButtonEdgeInsetsStyleBottom:
        {
            imageEdgeInsets = UIEdgeInsetsMake(0, 0, -labelHeight-space/2.0, -labelWidth);
            labelEdgeInsets = UIEdgeInsetsMake(-imageHeight-space/2.0, -imageWith, 0, 0);
        }
            break;
        case MKButtonEdgeInsetsStyleRight:
        {
            imageEdgeInsets = UIEdgeInsetsMake(0, labelWidth+space/2.0, 0, -labelWidth-space/2.0);
            labelEdgeInsets = UIEdgeInsetsMake(0, -imageWith-space/2.0, 0, imageWith+space/2.0);
        }
            break;
        default:
            break;
    }
    
    // 4. 赋值
    self.titleEdgeInsets = labelEdgeInsets;
    self.imageEdgeInsets = imageEdgeInsets;
}